The use of round patterns, i.e. cylindrical screen printing drums, in the screen printing of fabrics is known, a blade or roller within the drum pressing the printing ink or dyestuff through the unobstructed surface regions of the drum to imprint the fabric with the corresponding color patterns.
Such printing systems are described in the aforementioned copending applications, for example, and in the art of the files thereof.
It is known to provide such rotatable patterns in respective heads which are disposed one after another along the longitudinal path of the fabric to be printed and to pass the fabric between these heads and a support so that, as the drum rolls over the fabric, the pattern is printed in the manner described.
The patterns must, of course, be replaceable and for this purpose it is known to swingably mount the heads on fixed pivots, thereby enabling the head to be swung upwardly to afford access to the pattern and to permit such replacement.
When, however, a pattern drum or cylinder is replaced by a pattern drum or cylinder of larger diameter, the cylinder of this latter drum shifts relative to the cylinder of the drum which it replaced, thereby varying the pattern repeat.
This requires adjustment of the entire apparatus to match the center-to-center spacing of the drums to the desired repeat.